Taberang

It's not immediately evident, yet you need to assign a keyboard shortcut to the extension to get it working. If you go into the "Keyboard Shortcuts" section of the Extensions page, you'll find an entry for Taberang. Choose what you want for a Keyboard Shortcut and then you're all set.

Super useful. Someone send you a funny video but you want to wait until lunch to watch it? Taberang. Want to read a blog when you get home? Taberang. Want to reward yourself for an hour of focused work by reading a webcomic? Taberang. Using a browser window to monitor a long-running process and want to check on it in an hour? Taberang.

Doesn't work. The author's webpage says "I'm a programmer, that's all you need to know", with no feedback mechanism or any navigation options other than to sequentially go back through his blog - which has nothing to do with this extension.